Snap switch



, 1,466,820vl C. R. DUMBLE Sept. 4, 1923.

s mu"4 swITcH Filed June 8. 1921 2 Sheets-Sheet 1 Patented Sept. 4, 1923.

UNITEDl I STATES OFFICE.

CLIFFORDv R.I)UMBLE, OF ARLINGTON, MASSACHUSETTS, ASSIGNOR, BY MESNE AS- SIGNMENTS,l T0 THE LAMSON COMPANY, OF BOSTON, MASSACHUSETTS, A CORPO- RATION OF MASSACHUSETTS.

SNAP SWITCH.

Application led June 8,

To all whom it may concern.:

Be it known that I, CLIFFORD R. DUMBLE, a citizen of the United States of America, and resident of'Arlington, in the county of Middlesex and State of Massachusetts, have invented new and ,useful Improvements in Sna Switches, of which-the following is a specification.

This invention relates generally to a snap switch and is particularly applicable for use in connection with devices in which a rotary movement is employed for the actuation of the switch, and in which it is desirable to effect either an open or closed circuit for a certain period throughout a cycle of movements or operations.

One particular application of the switch is for use in connection with pneumatic tube systems in which an electric motor is intermittently energized for a predetermined period either to exhaust the air from, or create pressure in, the system. Heretofore, the switches employed in this connection have been actuated by a gate or other part of the pneumatic carrier system, and have depended upon a linear movement of a movable part of the system for the operation of the Switch. Such an arrangement has necessitated the use of various crank and lever connections, whereas in the present instance the switch may be directly and positively con- Y nected to and actuated by rotary movement of the gate bearing shaft, or other member movable when the carrier is inserted in the tube. In various installations it is at times necessary to mount the switch in di'erent relations, as for example in either a righthand or a left-hand position, in which case it is desirable to have a switch operable by either a clockwise or a counter-clockwise movement of the rotary actuator. Another desirable feature is to be able to vary the period through which the circuit is maintained or broken.

One of the objects of this invention is to provide a switch which will obviate the above objections, and'afford the desirable results above noted.

Other objects of the invention are to provide a switch which has few parts, which is simple in construction and durable in operation, which is economical to manufacture and is readily assembled, which is positive in action, which provides a quimpk make and 1921. serial No. 475,987.

break, which provides a `relatively wide break at a plurality of points, which may be actuated by a rotary movement either contlnuously in either direction or alternately in opposite directions, which may be employed interchangeably under different conditions, which is applicable for use in installations where a circuit is intermittently u sed for a certain period in a cycle of operations, which may be actuated by a relatively small movement and which has a. certain amount of free or lost movement, and in which a wiping or'cleaning action is obtained between the contacts.

Other objects and advantages will be apparent from the following description and the accompanying drawings in which Figure 1 is a top plan of the switch with the cover removed;

Fig. 2 is a bottom plan with the lcap an actuator removed;

Fig. 3 is a longitudinal section on line 3 3 of Fig. l;

Fig. 4 is a top plan of the support for the snap mechanism;

Fig. 5 is a side elevation of Fig. 4;

Fig. 6 is a top plan of the slide or carrier;

Fig. 7 is a side elevation of Fig. 6;

Fig. 8 is a longitudinal section on line 8-8 of Fig. l;

Fig. 9 is a bottom plan of the switch with the cap and insulating washer removed;

Big. 10 is a longitudinal section of a modified form;

Fig. 11 is a side elevation showing an application of the switch to a pneumatic carrier tube.

The switch as shown includes a base 10, which may be formed of any suitable insulating material, and spaced terminals 11-12 mounted thereon. The 'base is preferably provided with suitable openings 13-14 through which conductors may be passed for attachment to the terminals. l The terminals may be held in position bv any suitable means, such for example as screws 15. Suitable contacts 16-17 may be provided which are connected to the respective terminals 12-13 on opposite sides of an 'aperture 18 through the base. One end 19 of each of the contacts may be inserted below the base 2O of the terminal, and held by the same screw which holds the terminal in place, one side 16 of the contact face being bent outward at an angle to facilitate entrance of a cooperating movable contact.

The switch is of the snap type in which a quick make and break is provided. As shown, the mechanism for effecting the quick make and break action includes a slide or carrier member 21 which is mounted on a support 22 so as to be reciprocated thereon, the support being secured to the insulatin base by screws 23. An arm 24 is provided having a bridging contact 25 mounted at' one end thereof, the said contact functioning to comp-lete the circuit between the terminal contacts 16-17. The mechanism for effecting the quick make and break action is adapted to be applied to the base as a unit. v

The arm 24 is preferably pivotally supported at one end thereof on the reciprocating slide member 21, the arm being held upon its pivotal support by a spring 26, secured at one end to a pin 26 mounted therein, the other end being anchored or connected to the support 22 alon the path of the carrier at a point preferab y midway of the rest positions of the carrier, the purpose of such a relative arrangement of parts being to effect a quick snap action of the switch in making or breaking a circuit. The arm 24, the'carrier or slide 21, and the support 22, on which the slide reciprocates, are formed of metal stampings.

The 'arm 24 is preferably U-sliaped, havin at its ends projecting ear portions 27@I W ich are adapted to be seated in a suitable bearing 28 on the slide member 21. The other end of the arm is preferably provided with a forked or split portion 30 adapted to receive the bridging contact bar 25. The advantage of having the bridging contact 25 held within a forked structure is that the contact bar 25 is readily replaced, it being necessary merely to spread the forkportion to remove Ithe bar 25, after which another one may be replaced and securely positioned by bending the forked portions about the bar. It isr to be noted that no insulation is employed in mounting the contact bar 25 in the arm 24, and that a circuit between the terminal contacts is established directly through the contact bar 25, it being unnecessary that the circuit pass through a joint or connection of anyI character.

The support 22 is preferably formed with ears 31 through which screws may be threaded for securing the support to the insulating base 10. The support is provided at its ends,v with upwardly extending portions 32 which are so disposed as to function as stops for limiting the movement of the arm 24, the said portions also serving as abutments against which the arm may slide during the initial movement of the switch, prior to the snap action thereof. It is understood, however, that variousk other arrangements of parts may be employed to affect the functions above noted. For example, a lug 33 (see Fig. 10) may be formed integral with the insulating base to function as a stop for limiting the movement of the arm 24 and as an abutment against which it may slide. A bridging piece 34 is provided centrally of the support to which piece one end of the spring 26 may be anchored or connected.

The slide or carrier member 21 is provided with a pair of upwardly extending spaced ear portions 28 on opposite sides of the slide which form bearings for the projecting lugs or ears 27 at the end of the Ushaped carrier arm. The slide 21 is provided with a slot 37 through which the spring 26 extends, thus permitting reciprocation of the slide without interference with the spring. Lateral displacement of the slide 21 relative to the support 22 is prevented by downwardly extending lugs 38-39, one pair being arranged at each end of the slide. For the purpose of preventing lateral displacement of the slide it would be suiiicient that the length of the lugs should equal the thickness of the support. However, the lugs are extended a greater distance and cooperate with other mechanism to eect the reciprocation of the slide. It is desirable to provide means for ac tuatingA the switch which may be operable by continuous rotary movement in either clockwise or counter-clockwise direction, 0r by alternate rotary movement in opposite directions.v By providing an actuating means of this character, the switch may have numerous applications and may be employed in various relations and under different conditions. For example, in some applications, it is necessary to employ a switch in either a right-hand or left-hand relation. In the present switch, a simple and effective means is provided to meetthe above conditions. An actuating member, rotatably supported, is adapted to be rotated continuously in either clockwise or counter-clockwise direction, or alternately in opposite directions, either of which movements alternately effects the opening and closing of the snap switch. The actuating means comprises a radially extending cam or finger 40 rotatably mounted in a removable cap or cover 41 for the switch. A stud 42 is rotatably mounted in a suitable bearing bushing 43 fixed to the cover or cap 41, the finger or cam 40 being fixed to the end of the stud so as to be movable therewith. When in assembled position, the rotation of'the actuating member engages the downwardly projecting ears or lugs 38-39 of the slide member 21 for causing the reciprocation thereof, which in turn effects the movement or oscillation of the .arm 24 about an axis transverse of the path of downwardly extending lugs 38-39 are so positioned relativeI to the path of the finger or cam that rotation of the finger' 40 either clockwise or counter-clockwise will actuate the slide 21. For example, if the actuator is rotated clockwise the engagement of the finger 40 and upper ear 39 (Fig. 9) will continue until the slide has been moved to a position in which theI arm 24 is past dead-center position, whereupon the spring 26 snaps the arm and slide to the other position of rest. If the arm 40 is rotated in a counter-clockwise direction (F ig. 9) it engages the lower lug 38 and likewise throws the slide to the right.

The cap or cover 41 of the switch may be secured in position by any suitable means, such for example, as screws 44. The walls forming the passages 13, 14 through which the wires are led to the contact terminals` 11-12 extend below the surface of the insulating base 10 and serve as a guide and lbushing in positioning the cap 41 upon thc base 10 and also further prevents relative movement therebetween. The cover 41 is preferably formed of met-al and insulated from the finger or cam 40 and 'other metal parts of the switch by a washer 45 of insulating material between the cover 41 and the base l0. The insulating washer 45 and an insulating sleeve prevent the accidental short circuitin'g of parts of the switch of opposite polarity. By extending that portion of the base surrounding the openings through which the conductors are carried, below the general level of the base, the use ot' separable bushings of' insulation to protect the wires from accidental contact with thc metal cap 41 is rendered unnecessary. The entire switch may be enclosed by a suitable cover 51.

snap switch of the above character may bc contained in a relatively small space, and may be employed generally as a snap switch for actuation by hand. In applying the swiich to pneumatic tube carrier systems in which a motor is intermittently energized for a certain period, a switch of this character in which actuation is effected by a relatively small movement in one direction and permitting a relatively free movement in the same direction without affecting the operation of the switch` is particularly desirable. For example, in dispatching a carrier through a tube of a pneumatic system, the delivery end of the tube 47 (Fig. 11) is opened for reception of' the carrier byY raising a gate 48 a sufficient distance to permit the carrier to be inserted in the tube, after which the end of the tube is again closed by returning the gate to its original position. In affecting the above opera-tion, the gate 4S is rotated on its bearings 52 through a cer.- tain angle. which movement will rotate the shaft 53 sufiicientiy to aetuate the switch.

In assembling the switch, the support 22. the carrier or slide 21, the arm 24 and the spring 26 may be placed in their proper relative positions, these assembled parts constituting a unit which may be placed in the insulating base 10 in proper relative position with respect to the stationary terminal contacts 16--17 arranged on the base. lt is to be noted that the spring 2G serves to maintain the arm 24 in its bearing 28 upon the reciprocating slide 21, and also holds the slide 21 in position upon the support 22 as it is reciprocated thereon. 'The inclined upper part of the upwardly extending portion 32 functions as a stop for the oscillating arm 24 and the lower portion functions as a stop for the slide 21.

One advantage of the relative arrangement of the terminal contacts 16-17, with respect to the movement of the bridge contact or bar 25 and the mechanism effecting the movement. thereof, is that. the movement of the carrier and bridging Contact 25 is in a plane intermediate the terminal contacts so that a wiping action between the bridg ing contact and the tace of the terminal contacts is obtained, the effect of' which is to maintain a good contact and to keep the contact surfaces free from dust and other foreign matter. A further advantage of such arrangement is that a double break in the circuitis simultaneously effected by a snap action. lt is to bc noted that the sliding or wiping yaction of the contactbar upon the faces of the terminal contacts is not confined to the same path or surf-'ace when the circuit is made as it is when broken. When the contact. is established. the wiping action is effected as the contact bar is on its quick snap downward movement which is on the latter part of the path traversed by the 'contact bar in its movement from one position ,to the other. whereas when the circuit is broken the wiping action is effected by relatively slow upward 'movement of the contact bar through the first portion of the path traversed by the contact bar. A further advantage of such an arrangement is that the wear is distributed over a wider area, thus prolonging the life of these parts of the switch.

A switch of this character may be readily employed to control a plurality of circuits. This may readily be accomplishedv by providing ay second pair of terminal contacts, such as 50 (Fig. 10) disposed at the opposite sides of the switch base in a position corresponding to that occupied by the first pair of contacts. Separate terminals would of course be provided for the respective contacts. By the employment of two pairs of terminal contacts. one circuit would be interrupted and another circuit would be established.

The insulating sleeve 50' insulates shaft having a slot in its closed end, a contact bar removably secured in said slot, and means for imparting oscillatory movement to the arm whereby simultaneously to move the opposite ends of said bar into or out of contact with the respective terminals.

2. Switch mechanism comprising a pair of spaced, oppositely disposed terminals, a metallic lever arm pivotally mounted for oscillation in the space between said terminals, said arm having a recess in its free extremity, and a bar seated in said recess, and held therein by pressing the material of the arm inwardly over the bar, said bar being Aso constructed and arranged as simultaneously to contact with the respective terminals upon proper movement of the arm.

3. A snap switch comprising a pair of spaced terminals, a U-shaped arm pivotally supported at its open end to oscillate in a plane between said terminals, the closed end of said arm being bifurcated to form a recess, a contact bar seated in said recess and projecting to oppositesides of the arm, and means for imparting movement to the arm whereby simultaneously to move the opposite ends of said bar into and out of contact with the respective terminals.

4. A snap switch comprising an elongate base plate, a carrier slidable thereon, a pair of stops projecting upwardly from opposite end portions of the base plate, an arm having one end pivotally secured to the carrier and provided with contact means mounted upon its opposite end, a spring having one end secured to an intermediate point in said arm and at its opposite end to the central part of the base, and rotatable means for slidably moving said carrier whereby to swing said arm from engagement with one of said stop members into engagement with the other.

5. A switch comprising a base plate having an integral stop member upstanding from opposite ends thereof, a. carrier slidable-upon said base plate, lugs projecting downwardly from said carrier and embracing the base plate whereby to position the carrier relatively thereto, an arm pivotally secured lto the carrier and alternatively engageable with the aforesaid stops, and means for slidably moving the carrier.

6. In a snap switch of the type having a the slide, a spring interposed between the arm and anchor to snap the arm and slide, when moved part way from one position of rest into the other position of rest, and rotatable means engageable with an element of the carrier for reciprocating the latter.

7. In a snap switch of the type having a circuit terminal and a movable contact adapted to be moved into and out of contact with the terminal, snap mechanism comprising a-carrier or slide movable to andfro between positions of rest, an arm pivoted on the carrier to swing about an axis transverse of the path of the carrier between positions of rest, said contact being disposed on said arm so as to engage said terminal when the arm is in one position of rest, an anchor disposed along the path of the slide, and a reversibly rotatable actuator engageable with an element of lsaid carrier upon rotation thereof in either direction to move the carrier from either position of rest to a osition where it is snapped to the other position of rest by said spring.

8. In a snap switch of the type having a circuit terminal and a movable contact adapted to be moved into and out of contact with the terminal, snap mechanism comprising a carrier movable to and Jfro between positions of rest, an arm pivoted on the carrier to swing about an axis transverse of lthe path of the carrier between positions of rest, said contact being disposed on said arm so as to engage said terminal when the arm is in one osition of rest, an anchor dis` posed along t e path of the carrier, and a rotary actuator engageable with said carrier to move the carrier from one position of rest to a position where it is snapped to the other position of rest by said spring, the snap movement carrying the carrier into position to be engaged by the actuator for return to the first position when the actuator is rotated in either direction.

9. In a snap switch of the type having a circuit terminal and a movable contact adapted to be moved into and out of contact with the terminal, snap mechanism comprising a carrier movable to and fro between positions of rest, an arm ivoted on the carri'er to swing about an axls transverse of the path of the carrler between positions of rest,

Asaid contact being disposed on said arm so as to engage said terminal when the arm is in one position of rest, an anchor disposed along the path of the carrier and a rotary actuator for actuating said carrier, the actuator being rotatable about an axis intersecting the path of the carrier and having a radial arm, and the carrier having shoulders arranged in the path of saidl arm so that the carrier may be moved from either position of rest into position where it will be snapped to the other position of rest by rotating said actuator in either direction, said arm engaging different shoulders depending upon lthe direction in which it is rotated to move the slide in the same direction.

10. A switch comprising a carrier movable to and fro, a U-shaped integral arm pivotally mounted at its open end on said carrier to swing about an axis transverse of the path of the carrier, a coil spring interconnecting said arm with an anchor disposed along the path of movement of said axis so that the spring snaps the arm back and forth as the axis passes the anchor in the to-andfro movement of the carrier, a pair of terminals adjacent the path of said arm. and a removable contact member carried by the closed end of said arm and comprisin elements simultaneously enga eable wit the respective terminals when t e arm is snapped to one side.

11. A switch comprising a fixed terminal contact, an oscillatory contact engageable therewith, a reciprocable slide carrying said movable contact, and means including a rotary actuator for actuating said slide by a continuous rotary movement of the actuator in either direction.

12. A switch comprising a terminal contact, a movable contact, a carrier for moving said movable contact into and out of engagement with said terminal contact, an actuator adapted for continuous movement either clockwise or counter-clockwise and also for alternate clockwise and counterclockwise movement, and cam means for transmitting movement from said actuator to said carrier whereby to move the carrier alternately into open aTid closed circuit positions on any of said movements of the actuator.

13. A snap switch comprising a base plate, a carrier slidable thereon, elements projecting from said carrier and engaging said base plate whereby to position the carrier relatively to the base plate, lugs projecting from one face of the carrieroand providing bearings. an arm pivotally supported in said bearings, a tension spring connecting said arm with the central part of the base plate, and means for slidably movin the carrier.

14. A snap switch comprisin an elongate base plate, a carrier slidab e thereon, contact means mounted upon the carrier, lugs projecting ing opposite e ges of the base plate whereby from the carrierV and engagto guide the carrier in its movements, and a rotatable cam device engageable with said lugs for imparting reciprocatory sliding movement tothe carrier.

15. A switch comprising an elongate guide member, a carrier slidably engaging the same, said carrier having a pair of lugs pro- ]ecting from one face thereof :md a cam rotatable in a plane substantially parallel with the plane of movement of the slide member and engageable with said lugs for lmparting reciprocatory movement to the carrier.

16. A switch comprising circuit closing contacts, means for alternately opening and closing said contacts, said means including a reciprocable member, an actuator rotatably mounted, and means arranged between the actuator and the reciprocable member for alternately opening and closing the contacts by rotary movement of the actuator either continuously in either direction or alternately in opposite directions, said last named means including a plurality of pairs of ears movable with the reciprocable member and afinger rotatable with the actuator.

17. A switch comprising circuit closing contacts, means for alternately opening and closing said contacts, said means including a reciprocable member, an actuator rotatably mounted, and means including a plurality of pair of ears movable with the reciprocable member, a finger movable with ythe actuator and adapted to cooperate with the ears for effecting the operation of the contacts. said ears being spaced from each other and arranged in pairs on opposite sides of the reciprocable member, said finger being arranged to alternately cooperate4 with each one of a pair of ears on o-ne side of the reciprocable member when the actuator is alternately rotated in opposite directions. for effecting the opening and closing of the switch and to cooperate with one ear of each pair disposed on opposite sides of the reciprocable member when the actuator is rotated continuously in either direction.

18. In a snap switch of the type having a circuit terminal contact and a movable contact, snap mechanism including a reciprocable carrier for moving the movable contact into and out of engagementwith thev terminal contact, a plurality of pairs of projecon opposite sides of the carrier when said rae actuator is rotated continuously in either direction to effect the reciprocation of the carrier.

19. In a snap switch including a pair of contacts one of which is movable, snap mechanism for opening and closing said contacts including a reciprocating slide, an actuator rotatably mounted for reciprocating said slide, a plurality of ears projecting from said slide and arranged in spaced relation thereon, and a finger rotatable with said actuator adapted to alternately cooperate with adjacent ears when the actuator is rotated alternately in opposite directions to eect successively the opening and closing of the contacts by reciprocation of the slide.

20. In a snap switch including a pair of contacts one of which is movable, snap mechanism for opening and closing said contacts including a reciprocating slide, a support on which said slide reciprocates, an actuator for the slide rotatably mounted, means for guiding the slide pn the support including two pairs of ears arranged in rectangular form, one air being spaced on opposite sides of the side, said actuator having a linger rotatable therewith adapted to alternately engage one of each pair of ears on one side of the slide when rotated alternately in opposite directions, and to alternately engage i ears diagonally disposed from each other when the actuator is rotated continuously in either direction for effecting the opening and closin of the contacts.

2l. n a switch havin a pair of contacts, snap mechanism for eecting the opening and closing of the contacts including a reciprocating slide having a pair of downwardly projecting ears on each side thereof, a support between said ears on which the slide reciprocates, means for limiting the movement of the slide, and an actuator rotatably mounted adapted to cooperate with' the sllde to reciprocate the same by rotary movement either alternately in opposite directions or continuously in either direction, said actuator including a radially extending finger adapted to be rotated between said pairs of ears whereby when the actuator is rotated alternately' in opposite directions thc finger will alternately engage each one of a palr of ears on one Side of the slide, and when the actuator is rotated continuously in either direction the linger will alternately engage one of each pair of ears on opposite sides of the slide, said ears being diagonally disposed fro-m each other.

22. A switch comprising guide means, a carrier slidably engaging said guide means, a contact member movable with the carrier, two pairs of spaced elements proecting from the carrier, and a cam rotatable in a plane substantially parallel to the plane of movement of the carrier, said cam being i constructed and arranged to engage the eleof contacts one of which is mova le and snap mechanism for said movable contact, means including an actuator for imparting to said snap mechanism rotary movement alternately in opposite directions or continuously in either direction, said means comprising a sliding carrier having two pairs of projecting ears spaced and arranged parallel to each other in pairs so as to form a parallelogram, said actuator bein mounted to rotate about an axis passin trough the path of said carrier, and a r l'ally extending linger movable with the actuator and adapted to alternately engage each one of a pair of ears on one side of the arallelogram when said actuator is rotatedpalternatel in opposite directions, said finger beinga apted to successively cooperate with one of each of the pairs of ears, said ears being diagonally disposed from each other when said actuator is rotated continuously in either direction.

24. A switch comprising an insulating base having opening therein for the passage of conductors, annular projectin iianges surrounding said openin switc mechanism mounted upon said bise, a cover plate having openings for the passage rf the respective flan s whereby the cover late is positioned re atively to the base, an means for securing the cover plate to the base.

25. A snap switch comprising in combination, a plurality of contacts, one of which is movable, an arm for said movable contact, and snap mechanism for said movable contact, said snap mechanism includin a slide having a pivotal support for one en of said arm, stops limitin the movement of the slide in each direct1on, a spring having one end secured to the arm and the other end :fixed at a point approximately midway between the stops whereb said movable contact is snapped into an out of engagement l with the other contact upon reciprocation of the slide, means including an actuator rotatably mounted for reciprocating said slide by rotary movement either alternately in o posite directions or continuously in either ,d1rection, said last-named means including 26. In a snap switch of the character described having a plurality of contacts, one of which is movable, and snap mechanism cooperating therewith, means including a rotary actuator for alternately effecting the opening and closing 0f said contacts by eithera rotary movement alternately in opposite directions or continuously in either direction, said means comprising a support having stops thereon, a slide adapted to be reciprocated upon said 'support between said stops, two pairs of ears extending downwardly from said slide, one pair ot' ears being arranged on opposite sides of said slide and serving as guides for maintaining said slide in proper position upon the support,

the said ears being arranged substantially in the form of a parallelograln, and a radially extending finger carried by said rotary actuator adapted to cooperate. with said ears for effecting the reciprocation of said slide when said actuator is rotated altrenately1 in opposite directions or continuously7 in either direction, the axis about which said actuator rotates passing through apoint intermediate the sides of the parallelogram and approximately midway between the stops limiting the movement of the slide.

Signed by nie at Boston, Massachusetts, this twenty-fourth day of May, 1921.

CLIFFORD R. DUMBLE. 

